【摘要】 提出一种新型蛇型挡板流道设计,该流道设计是通过在传统蛇型流道中添加挡板构成的。三维数值分析表明,当操作电压下低于0.7V时,蛇型挡板流道设计性能较传统蛇型流道有较大提高。分析电池内部氧气流量、液态水和局部电流密度发现,添加挡板增大了流道内燃料压力,电池内部受肋下对流效应影响的区域增大,由于肋下对流效应不仅提高了肋条下方多孔层氧气传输效率,同时在多孔层内产生较大的对流剪切力还可有效提高液态水移除效果,因此性能提高。压力损耗分析表明,尽管蛇型挡板流道增大了电池压损,但对本文所分析的小型燃料电池而言,增加压损引起的附加压缩功远小于电池输出功,因此压损可不予考虑。更多还原

【Abstract】 A new serpentine-baffle flow field (SBFF) design was proposed by adding the baffles in the conventional serpentine flow field (SFF). Three-dimensional numerical model shows that the SBFF design has a better performance than the SFF design at the operating voltages lower than 0.7 V. Analyzing the local oxygen mass flow rate, liquid water and current density indicate that the SBFF design enhances mass transport capability and liquid water removal efficiency as a result of the enhanced under-rib convection associated with the increased pressure difference between adjacent flow channels and forced convection near baffles. Compare with the SFF design, the pressure drop for the SBFF design increases, the pressure drop loss is far less than the cell output power, and then additional compressor power can be ignored.更多还原